제진 보강 평판의 진동 특성에 관한 연구

The purpose of this paper is to investigate the natural frequencies of stiffened plates due to transformation of stiffener shape and existence of viscoelastic resin. To verify vibration characteristics, local stiffness matrix and local mass matrix are calculated by using F.E.M including plate and beam theory. In case of stiffened plate with viscoelastic resin, the natural frequency of each mode is decreased about 10 ~50 percent at quadrilateral form stiffener and about 10 ~ 40 percent at triangular form stiffener. In case of viscoelastic resin of quadrilateral and triangular form, the higher the height of stiffener is, the higher the natural frequency is at the first mode. But the natural frequencies beyond the second mode are known to unrelate to the height of stiffener. In case of stiffened plate with quadrilateral form stiffener and without resin the numerical values by using F.EM are about 5 ~ 10 percent higher than those of experiment.